Reconstructed internal combustion engine cylinder heads and method of making same



NOV. 7, 1967 E MORRISON 3,351,043

RECONSTRUCTED INTERNAL COMBUSTION ENGINE CYLINDER HEADS AND METHOD OF MAKING SAME] Filed Dec. 29, 1966 2 Sheets-Sheet 1 INVENTOR 35 BY [0mm MZffl/mv ATTORNEY Nov. 7, 1967 E. MORRISON 3,351,043

RECONSTRUCTED INTERNAL COMBUSTION ENGINE CYLINDER HEADS AND METHOD OF MAKING SAME Filed Dec. 29, 1966 2 Sheets-Sheet 2 ATTORNEY United States Patent O 3,351,043 RECONSTRUCTED INTERNAL COMBUSTION EN- GINE CYLINDER HEADS AND METHOD OF MAKING SAME Edward Morrison, 176 Oxford Road, New Rochelle, N.Y. 10804 Filed Dec. 29, 1966, Ser. No. 605,662 12 Claims. (Cl. 123-32) ABSTRACT OF THE DISCLOSURE The repair and reconstruction of a diesel engine cylinder head with a cracked wall. The cylinder head in its reconstructed form includes a plug of hard compact material supporting the fuel injector in proper position, the plug having a portion thereof in threaded engagement with the wall, and another portion welded to the wall. The method comprises steps for the removal of the cracked portion and the securing and sealing of the plug to the cylinder head wall.

BACKGROUND OF THE INVENTION The field f the invention This invention relates to reconstructed internal C0111- bustion engine cylinder heads, and is a further development of the invention of U.S. Patent No. 3,187,729 dated July 8, 1965.

Reference to the prior art It is an object of this invention to produce repaired diesel cylinder heads having not only all the advantages over the prior art of the invention of said Patent No. 3,187,729, but also certain improvements over the invention of said patent. The said advantages of said patented invention retained by the present invention include, among others, the ready repair of a damaged diesel cylider head by reconstructing it so that the repaired head is free of air pockets at the critical region adjacent the injector and is free of the danger of water leaks resulting from such air pockets, so that the repaired portion has sufficient structural strength to withstand the required torques for installing the injector unit and to rigidly support the unit in place, and is provided with a hard, nondeformable, accurately ground and thoroughly sealed seat for the precombustion chamber of the injector unit.

The improvements of the present invention over the said patented invention reside in the lowering of the cost of machining the plug unit, in the firmer support of the plug in the cylinder wall, in the more perfect alignment of said injector unit, and in the provision for expansion and contraction of the material at the critical area adjacent the water jacket, all as will hereinafter appear.

SUMMARY OF THE INVENTION In the said patented invention, a hollow plug of hard compact material is positioned within the firing deck wall of the engine cylinder head, said plug being welded to a recessed portion of said wall and being internally threaded for supporting a fuel injector unit. In the practice of the said invention it is necessary to perform the drilling and threading operation in the plug after it has been operatively welded to the cylinder, rather than to follow the more economical procedure of performing these operations before the plug is afiixed to the cylinder wall. The reason for following this less economical procedure is that the mass of Welding material securing the plug in place cannot be relied upon to maintain it in the precise predetermined position at which a predrilled and prethreaded plug must be held for proper longitudinal positioning of the attached injector. This is due to the fact that the welding material is at times subject to distortion under the prevailing thermal conditions whereby the plug may settle itself in a position somewhat displaced from its intended axially longitudinal position.

In the present invention a similar plug of hard, compact material is employed, this plug, however, being predrilled and prethreaded, and in addition, provided with an external thread adapted for threaded engagement with a corresponingly positioned internally threaded portion of the cylinder wall. Since threading operations can be performed with great precision, the threaded engagement of the plug with the cylinder wall assures a perfect longitudinal axial positioning thereof. To further assure the maintenance of the plug in said position, it is provided with a flanged base adapted for underlying engagement with the surface of the cylinder wall exposed to the water jacket. Since the threaded engagement of the plug with the cylinder wall does not provide the required perfect seal for preventing leakage from the water jacket into the firing chamber, the present invention further provides an annular weld deposit around the plug at the region thereof adjacent the firing chamber, such welding being effective in the prevention of leakage. Hence, by means of this invention, the plug can be machined into its final form in the most economical manner, that is, by performing the machining operations on the plug before it is assembled in place, the arrangement being such that a properly positioned plug and injector is readily effected in a leak-proof structure.

It also has been found that in practicing the said patented invention, cracks or fissures tend to appear in the cylinder Wall adjacent the water jacket even when the wall adjacent the firing chamber shows no sign of damage. This has been determined to be due to the fact that the plug is maintained in place by one homogeneous mass of welding material, providing no space for the different degrees of expansion and contraction between the plug portion and the thin cylinder wall portion adjacent the water jacket where, especially during the starting period, there is a relatively great temperature difference between the portions in engagement with the water and regions spaced therefrom. To alleviate this situation, the present invention employs no welding material between the cylinder wall and the plug lat the region adjacent the water jacket, but instead employs threaded means for securing the plug in place the-reat. This provides clearance spaces between the coacting threaded portions of the cylinder wall and plug to permit differential expansion and contraction between the plug and Wall, and at the same time provides a substantial thickness of cylinder wall at said region instead of the thin section at the water jacket juncture of the plug and cylinder wall of said patented invention. The special feature of this aspect of the invention is that the above-mentioned threaded portion of the cylinder wall in engagement with the plug serves the double purpose of providing for the aforesaid expansion and contraction differentials between the wall and the plug and at the same time effecting the required accurate connection between the plug and the wall. Should there be any leakage of water through such threaded connection, the aforementioned weld material surrounding the plug in the region of the firing deck will provide a positive seal, as aforesaid.

Other objects, features and advantages will appear from the drawings and the description hereinafter given.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary bottom perspective view of a damaged diesel engine cylinder head prior to repair and reconstruction in accordance with the method and structure of this invention.

FIG. 2 is a somewhat enlarged bottom view of a portion of the cylinder head of FIG. 1.

FIG. 3 is an enlarged fragmentary section of FIG. 2 taken along line '33, showing a conventional fuel injector unit with precombustion chamber operatively in place.

FIG. 4 is an enlarged sectional representation of a portion of the cylinder head shown in FIG. 3, the injector unit having been removed.

FIG. 5 is a fragmentary sectional view of the portion of the cylinder head shown in FIG. 3, illustrating the reconstructed portion according to the above-mentioned patented invention operatively accommodating the fuel injector precombustion chamber unit.

FIG. 6 is a front elevation, partly in section, of the fully fabricated plug unit of the present invention.

FIG. 7 is a fragmentary section of the portion illustrated in FIG. 4, but showing said portion after the removal of the precombustion chamber seat and the damaged stock by a machining operation in accordance with a step in the method of this invention.

FIG. 8 is a View like FIG. 7, but showing the plug of FIG. 6 operatively in place according to a subsequent step of the method of this invention.

FIG. 9 is a view like 'FIG. 8, but showing the further welding step of the present invention and illustrating the reconstructed cylinder head portion prior to attaching the injector unit in place.

FIG. 10 is a fragmentary sectional view of the portion of the cylinder head shown in FIG. 3 illustrating the reconstructed portion operatively accommodating the fuel injector precombustion chamber unit.

DESCRIPTION OF PREFERRED EMBODIMENT In the form of my invention illustrated, the fragment of the damaged cylinder head illustrated in FIG. 1 shows a section thereof adapted for coactive positioning with respect to a correspondingly positioned cylinder on a cylinder block not shown. This section contains the inlet valve port 16, exhaust valve port 17 and the apertured portion 18 for the fuel injector. In the particular cylinder head fragment illustrated, a small crack 19 is shown extending down from the firing deck surface 20 to the water jacket surface 21 defining a part of the water jacket 26, said firing deck surface being adapted for operative positioning adjacent a coactive cylinder. The said water jacket is flanked by the walls 22 and 34, the former, at times hereinafter referred to as the inner wall, being defined by said surfaces 20 and 21.

In the said conventional structure shown in FIG. 3, the said apertured portion is a passageway 18 extending from the said surface 20 through the said inner wall 22 to the face 23 of the boss 24, the internal annular wall of the apertured portion 18 being threaded along the extent thereof. Welded to said boss 24 is the centrally apertured seat 25. The fuel injector unit 27 comprises the outwardly threaded fuel injecting portion 28 and the precombustion chamber 29-the said portion 28 being in threaded engagement with the threaded wall of the apertured portion 18, the said chamber 29 having a shoulder 30 in abutting operative engagement with the surface 31 of said seat 25, the opposite outer end portion 32 of the chamber 29 extending through the aperture 33 in the said outer wall 34 supporting the sealing ring 35 in annular engagement with the said end portion 32 of chamber 29. The said respective intake and exhaust ports 16 and 17 are in operative communication with the respective passageways 36 and 37 in a manner known to those skilled in the art.

The structure of said patented invention is illustrated in FIG. 5 for clarifying the nature of the improvements thereover of the present invention. The figure shows a plug 38 made of hard, closely grained and compact metal, preferably cast iron, the plug comprising a frustoconical body portion secured in place by a mass of weld material 39 surrounding said body portion, the said plug having a central aperture defined by an inner annular threaded wall 40 with which the fuel injector is in engagement. In this arrangement it will be noted that the widest portion of the weld material is adjacent the surface 20, the lowermost portion of said weld material being a thin peripheral section 41 adjacent the water jacket 26. As aforesaid, the said threaded annular wall 40 is formed after the plug 38 has been positioned in place. Due to the fact that the plug 38 is maintained in position and secured to the cylinder wall by the mass of weld material 39, there is no provision for expansion and contraction differentials between the plug 38 and said peripheral wall portion 41. As hereinabove indicated, the region of the said peripheral portion 41 tends to crack, or become warped. It is one of the objects of this invention to eliminate conditions of stress due to the lack of provision for expansion and contraction in the water jacket region, and thereby obviate the creation of cracksan objective accomplished by the present invention in the manner hereinbelow set forth.

In the practice of this invention, as in that of the said patented invention, the injector unit 27 and the ring-like seat 25 are first removed from the cylinder wall. Then, by means of a suitable machine tool, the damaged stock of wall 22 adjacent the apertured portion 18 is removed, this operation resulting in the formation of an enlarged cavity 42 (FIG. 7) extending part of the way down from surface 20, the concave lateral side 43 which defines said cavity being flared outwardly from the bottom 43a of the cavity towards said firing deck surface 20. A hole 44 is then drilled in said wall 22 between bottom 43a of cavity 42 and said water jacket surface 21, thereby forming a through passageway between the region of the jacket and the said cavity 42. Thereafter the annular wall 44a defining said hole 44 is threaded by means known to those skilled in the art. The said cavity 42 and said hole 44 together constitute the apertured portion into which the plug 45 extends, as will hereinafter appear.

The said plug 45, provided for by this invention, is made of hard, closely grained and compact metal like that of the aforesaid patented invention. The preferred form of plug comprises a cylindrical body portion 46 and a bottom flange 47, the outer cylindrical surface 48 having a threaded portion for operative engagement with the said threaded annular wall 44a, and the inner annular wall 49 being threaded to receive the outer threaded section 28 of the said injector unit 27. The said flange 47 contains an annular recess 50 extending upwardly from the bottom surface 51 of the plug 45, thereby providing a properly ground seat 52 to receive the shoulder 30 of the injector unit. The said plug 45 is then inserted through the said hole 44, the outer threaded wall 48 being in threaded engagement with the annual wall 44a of the wall 22 (FIG. 8), the upper surface 53 of said flange coming to rest against the surface 21 of said wall 22. It will be noted that, in the form illustrated, the height of the body portion 46 is equal to the thickness of the wall 22, so that the upper surface 55 of the plug is substantially level with the surface 20 of said wall 22. The plug is now aflixed in proper axial position within the hole 44 of wall 22, and will be maintained in such position due to the substantially nonyieldable properties of both the plug 45 and the wall 22.

The next step is that of depositing sealing material 54 Within the said cavity 42, whereby the upper part of the body portion 46 of the plug is in engagement with said sealing material. It is preferred that this sealing material be weld material applied by conventional welding process. The weld seal between the weld material and the plug is as effective in sealing the wall 22 against water leakage as the welding employed in said patented invention.

The aforesaid welding step completes the repairing operation, and the cylinder head is now prepared to receive the injector unit 27. The assembled unit is illustrated in FIG. 10. This view clearly illustrates the firm positioning of the plug 45 in place by the firm threaded engagement between the said plug and the wall 22. Although a firm securement is thus effected, with practically no possibility of plug displacement or misalignment there is still some clearance between the threads of the plug and the operatively engaged threads of the wall 22 by the very nature of threaded connections. Hence, in the region A where, as aforesaid, there is need for relative freedom of expansion and contraction of the adjacent plug and Wall material, the clearance between the threads provides such freedom in a manner not possible with the complete weld connection of the said patented invention between the main body of the plug and the Weld material. The threaded portion T (FIG. 9) between the bottommost portion 56 of the weld material 54 and the juncture 57 between the body portion 48 of the plug and the flange 47 thus serves a double function, that of determining the correct position of the plug and maintaining it against displacement from such position, and that of providing room for differential expansion and contraction of the materials at the said critical portion A.

It is thus apparent that the present invention, while having all the advantages of the said patented invention, nevertheless constitutes a substantial improvement thereover in that it permits of a lower machining cost of the plug unit, effects firm and correct positioning of the injector unit, and permits relatively greater freedom of expansion and contraction between the plug and adjacent material of the cylinder head.

In the above description, the invention has been disclosed merely by way of example and in preferred manner; but obviously many variations and modifications may be made therein. It is to be understood, therefore, that the invention is not limited to any form or manner of practicing same, except insofar as such limitations are specified in the appended claims.

I claim:

1. In a repaired internal combustion engine cylinder head casting having a water jacket and being adapted for operatively receiving a fuel injector unit, said head having an inner wall adjacent said jacket and defined by a firing deck surface and a water jacket surface, the combination of a portion of said inner wall having an aperture therein extending therethrough between said surfaces, said aperture comprising an open-ended laterally enclosed cavity extending from said firing deck surface partly through said inner wall and a cylindrical opening of lesser transverse proportions than that of said cavity and extending from said cavity to said water jacket surface, a hollow plug of said compact material disposed within said aperture, a part of the outer surface of said plug being in threaded engagement with the cylindrical wall defining said cylindrical opening, and sealing means within said cavity and in sealing engagement with the adjacent part of said plug, said sealing means being weld material operatively joined to the adjacent portions of said plug and the apertured portion of said inner wall, said plug having an internal apertured portion adapted for operative supporting engagement with said fuel injector unit.

2. In a repaired internal combustion engine cylinder head, the combination according to claim 1, said plug having a flange disposed within said water jacket and being in engagement with said water jacket surface of said inner wall.

3. In a repaired internal combustion engine cylinder head, the combination according to claim 2, said flange having a seat portion proportioned and positioned for engagement with a portion of said injector unit when said unit is operatively positioned within said plug.

4. In a repaired internal combustion engine cylinder head having a water jacket and being adapted for operatively receiving a fuel injector unit having an intermediate annular shoulder, the combination according to claim 2, said flange having a recessed annular seat proportioned and positioned for operative engagement with said annular shoulder of said injector unit when said unit is operatively positioned within said plug.

5. In a repaired internal combustion engine cylinder head, the combination according to claim 2, said plug having a body portion joined to said flange and being of a length substantially equal to the thickness of said inner wall, whereby the free end of said body portion is substantially flush with said firing deck surface.

6. In a repaired internal combustion engine cylinder head, the combination according to claim 1, said internal apertured portion of said plug being threaded for operative threaded supporting engagement with said injector unit.

7. In a repaired internal combustion engine cylinder head, the combination according to claim 1, the region of said threaded engagement of the outer surface of said plug with said apertured portion of said inner wall being adjacent said Water jacket surface, said sealing means being adjacent said firing deck surface.

8. In a repaired internal combustion engine cylinder head, the combination according to claim 1, said cavity being flared outwardly from the region of said internally threaded annular wall toward said firing deck surface, said sealing means being weld material operatively joined to the Wall defining said cavity and the adjacent portion of said plug.

9. In a method of repairing a jacketed diesel engine cylinder head casting having an inner Wall adjacent the jacketed portion and defined by a firing deck surface and a water jacket surface and containing a cylindrical aperture adapted for operatively accommodating a fuel injector unit, said wall having a cracked portion therein in the region of the wall of said aperture, the step of removing a predetermined portion of the stock of said inner Wall which includes said cracked portion by forming a cavity extending from said firing deck surface to an intermediate portion of said wall in spaced relation to said water jacket surface and drilling a hole through said wall from said intermediate portion thereof to said water jacket surface, forming a threaded portion on the Wall defining said drilled hole, providing a hollow injector-supporter plug of hard compact material having a body portion substantially of the same extent longitudinally as said apertured portion, at least a part of said body portion being threaded-and proportioned for engagement with said threaded portion, inserting said plug into said apertured portion with said threaded parts in operative engagement and with another part of said plugs body portion extending through said cavity and applying sealing material within said cavity and into sealing engagement with the adjacent part of said body portion.

10. In a method of repairing a jacketed diesel engine cylinder head, casting the steps according to claim 9, the diameter of said drilled hole being less than the transverse proportions of said cavity, the said step of forming a threaded portion comprising the step of threading the annular wall defining said drilled hole, the said step of applying sealing material comprising the step of opera tively depositing said material in said cavity.

Z 8 11. In a method of repairing a jacketed diesel engine References Cited cylinder head, the steps according to claim 10, said step of UNITED STATES PATENTS applying sealing material comprising the step of operatively depositing welding material in said cavity and there- 2,858,813 11/1958 Haas 123-32 by Welding together the said unthreaded parts of the plug 5 3,140,697 7/1964 Peras 12332 and apertured portion of the said inner Wall. 3 17 4 19 5 Whithead 123 193 X 12. In a method of repairing a jacketed diesel engine cylinder head, the steps according to claim 11, the said provided plug having a flange joined to said body portion, the said step of inserting the plug including the step of 10 MARK NEWMAN Examme" bringing said flange into engagement with said water L RENCE M. GO DRIDGE, Examiner. jacket surface.

3,187,729 6/1965 Morrison 12332 

1. IN A REPAIRED INTERNAL COMBUSTION ENGINE CYLINDER HEAD CASTING HAVING A WATER JACKET AND BEING ADAPTED FOR OPERATIVELY RECEIVING A FUEL INJECTOR UNIT, SAID HEAD HAVING AN INNER WALL ADJACENT SAID JACKET AND DEFINED BY A FIRING DECK SURFACE AND A WATER JACKET SURFACE, THE COMBINATION OF A PORTION OF SAID INNER WALL HAVING AN APERTURE THEREIN EXTENDING THERETHROUGH BETWEEN SAID SURFACES, SAID APERTURE COMPRISING AN OPEN-ENDED LATERALLY ENCLOSED CAVITY EXTENDING FROM SAID FIRING DECK SURFACE PARTLY THROUGH SAID INNER WALL AND A CYLINDRICAL OPENING OF LESSER TRANSVERSE PROPORTIONS THAN THAT OF SAID CAVITY AND EXTENDING FROM SAID CAVITY TO SAID WATER JACKET SURFACE, A HOLLOW PLUG OF SAID COMPACT MATERIAL DISPOSED WITHIN SAID APERTURE, A PART OF THE OUTER SURFACE OF SAID PLUG BEING IN THREADED ENGAGEMENT WITH THE CYLINDRICAL WALL DEFINING SAID CYLINDRICAL OPENING, AND SEALING MEANS WITHIN SAID CAVITY AND IN SEALING ENGAGEMENT WITH THE ADJACENT PART OF SAID PLUG, SAID SEALING MEANS BEING WELD MATERIAL OPERATIVELY JOINED TO THE ADJACENT PORTIONS OF SAID PLUG AND THE APERTURE PORTION OF SAID INNER WALL, SAID PLUG HAVING AN INTERNAL APERTURED PORTION ADAPTED FOR OPERATIVE SUPPORTING ENGAGEMENT WITH SAID FUEL INJECTOR UNIT. 